丹参酮ⅡA对局灶性脑缺血大鼠急性期脑保护作用的相关研究

Protective Effect of Tanshinone IIA during the Acute Stage of Focal Cerebral Ischemia in Rats

目的探讨丹参酮ⅡA(TashinoneⅡA,TSA)对局灶性脑缺血急性期大鼠顶叶皮质磷酸化环腺苷酸反应元件结合蛋白(phosphorylated cyclic adenosine monophosphate response element binding protein,p-CREB)和CREB1活性调节转导子(transducers of regulated CREB1,TORC1)的蛋白表达和脑梗死体积的影响。方法采用成年健康雄性SD大鼠,随机分为假手术组、对照组、小剂量TSA组和大剂量TSA组,每组各12只。用线栓法制作右侧大脑中动脉闭塞模型,采用Longa评分判断动物模型成功与否。小剂量TSA组和大剂量TSA组在造模后立刻腹腔注射TSA溶液,剂量分别为:10 mg/kg及20 mg/kg,假手术组及对照组分别腹腔注射等量的生理盐水。造模成功后24 h将大鼠处死,采用2%2,3,5-三苯基四唑氮红染色计算梗死体积,应用Western blotting法检测各组手术侧顶叶皮质梗死灶神经细胞核TORC1和细胞核p-CREB以及细胞TORC1的蛋白表达。结果与对照组相比,大剂量TSA组大鼠脑组织梗死体积明显降低(P=0.004),细胞核TORC1表达显著增加(P<0.001);与对照组相比,小剂量TSA组大鼠脑组织梗死体积减小,无显著差异(P=0.148),细胞核TORC1蛋白表达升高,也无显著差异(P=0.083),细胞核p-CREB和细胞TORC1的蛋白表达水平无论在大剂量组(P均<0.001),还是小剂量组(P分别为0.002和0.001)均显著升高。结论 TSA可以上调脑梗死大鼠病灶侧顶叶皮质神经细胞TORC1-CREB信号通路的表达。

Objective To investigate the effect of tanshinone IIA （TSA） oil the protein expression of phosphorylated cyclic adenosine monophosphate response element binding protein （p-CREB） and transducers of regulated CREB1 （TORC1） and volunle of cerebral infarction in rats＇ parietal cortex during focal cerebral ischemia. Methods Male Sprague-Dawley rats were randomly divided into sham group, control group, TSA low dose group and TSA high dose group, twelve in each group. Focal cerebral ischemia model was induced by occlusion of the right middle cerebral artery using the intraluminal suture method. The rats were scored after waking up. 2, 3, 4 or 5 scores were brought into this study. TSA solution （ 10 mg/kg, TSA-L; or 20 mg/kg, TSA-H） was injected intraperitoneally immediately after the rats waked tip. The rats were scored and sacrified at 24 h alter waking up. Infarct size was analyzed with 2, 3, 5-triphenyltetrazolium chloride （TTC）. Western blotting was used to analyze the protein expression of TORCI and p-CREB of each group in the nerve cell, and the positive products were analyzed by image analysis system. Results Compared with control group, the infarct size of TSA-H group was significantly decreased （P=0.004）. And nuclear accumulation of TORCI was only significantly increased in TSA-H group（P〈0.001）. Compared with control group, the decrease of the infarct size in TSA-L group and the increase of nuclear protein expression of TORC1 have no remarkable differences （P=0.148, P=0.083, respectively）, the expression of TORCI （Total） and p-CREB （Nucleus） protein level in TSA-H （P〈0.001） and TSA-L （（P=0.002, P=0.001 ） group was significantly increased, the enhanced TORC1 is localized in the nucleus and cytoplasm of neurons. Conclusion TSA could protect rat brain from ischemic damage and upregulate the expression of TORC 1 -CREB pathway in rats＇ parietal cortex during focal cerebral ischemia.